1. Field of the Invention
The invention relates to switchable gearboxes of a handheld power tool, especially a handheld driver/drill, having an axial direction and a gear arrangement that is movable in the axial direction of the gearbox and is switchable between first and second switching stages. The invention moreover relates to a handheld power tool.
2. Description of the Related Art
Handheld power tools such as power drills, driver/drills and the like have switchable gearboxes that can be switched between at least two switching stages. The two switching stages can be a first speed and a second speed with different initial rotary speed or rpm (revolutions per minute). However, it is also possible to switch between a right-handed and left-handed rotation, between drilling and screwing operation, and the like. Accordingly, the power tools have therefore an external manual actuator for effecting a switching action.
Within the gearbox, an axially movable gear arrangement is provided that is movable by means of the actuator between two different axial positions. The aforementioned gear arrangement engages different counter gears, a coupling member, a lock member, or the like.
An axial movement of the gear arrangement requires an exact alignment, for example, with the toothing of an additional gear, with a locking member or the like. Without proper alignment, switching can be difficult and requires a sensitive handling.
The occurring operating loads, in particular, in connection with a spiral gearing, in connection with changing rotational direction in screwing operation or the like, can cause great forces to act on the movable gear arrangement. Under unfavorable circumstances, this causes the gear arrangement to jump out of the selected switching stage.